Fuel ignition system



Sept. 25, 1'945., v v. A. Fox

FUEL IGNITION SYSTEM .I

Filed Sept. 8,- 1941 3. l V .J6

1v v l ze ze l Gttomegs Patented Sept. 25, 1945 UNITED STATES PATENT vOFFICE FUEL IGNITION SYSTEM Vernie A. Fox, Detroit, Mich.

Application September 8, 1941, Serial No. 410,018 3 Claims. (Cl. 158-28) This invention relates, in general, to ignition systems and, in particular, to one employable in conjunction with fuel ignition.

One of the objects of the present invention is to provide a new and improved fuel ignition system which operates with the highest degree of simplicity, economy and safety and the parts of which are readily and easily inter-assembled or dis-assembled. Another object is to provide a new and improved fuel ignition system the igniter of which is faultlessly certain to acquire a temperature at least as high as the ignition temperature of the fuel before the latter begins to flow.

Another object is to provide a new and improved fuel ignition system wherein fuel flowage is faultlessly certain to cease in the event of ignition failure.

Another object is to provide a new and improved fuel ignition system which is unaffected by local pressure conditions, such as suction or drafts.

Another object is to provide a new and im proved fuel ignition system wherein the parts' are simple and inexpensive in construction and novel and compact in arrangement.

Other objects and advantages of the invention will become readily apparent from a reference to the following specification taken in conjunction with the accompanying drawing, wherein:

Figure 1 is a longitudinal sectional view of my new and improved igniter device;

Figures 2 and 3 are sections taken along the lines 2--2 and 8 3, respectively, in Figure i;

Figure 4 is a diagrammatical view of a system which is particularly adapted for having my device incorporated therewithin; and

Figure 5 is an elevational vview of my device shown in a slightly different use than in Figure 4.

My igniter consists of a tubular shell, support, body, guard or duct I0 which is open at its ends and carries therebetween, preferably permanently, a fuel inlet-forming member l2 through which fuel may flow (from a source to be described) for entering the interior of said duct, and, if desired, the flow path defined by said member may have installed therein a section of mesh I4 for preventing foreign matter from travelling therepast. One of the two ends of duct Il is to serve as a flame outlet therefor, andthis outlet may be supplemented, if desired, by other outlets I6 formed through and around the wall of said duct adjacent said one end.

The opposite end of duct III isformed to carry,

, said duct and the fuel inlet thereof.

either removably or irremovably, and be closed by an insulated cap, cover or support I8 which provides an anchorage for a pair of terminal posts 28 and 22, these posts having bar-like conductors 24 and 26 secured thereto in electrical continuity therewith and extending forwardly therefrom in spaced relation to each other into positions intermediate the flame `outlet end of The forward ends of conductors 24 and 26 are bifurcated, as at 28' and 30, respectively, so as to provide for the holding of a resistance coil 32, one end of said coil residing between the arms of said bifurcated portion. 28 and the other end residing between the arms of said bifurcated portion 80, the coil proper extending forwardly toward the flame outlet end of duct I0. As shown, fasteners 34 are employed for tightening the arms of portions 28 and Ill with respect to the ends of coil 32 held thereby. Furthermore, an insulated support 36 is carried within duet I0 to receive portions 28 and I8 and hold same in place with respect to each other, said support having a substantially tight fit with the inner wall of said duct and being formed therethrough and therearound with ports 38 for intercommunicating the interior portions of said duct on opposite sides of said support- Before discussing the operation of the igniter device hereabove described, attention is directed toFlgni, wherein said device is shown as being employed in conjunction with a standard fuel burner 40, said burner'having its inlet connected,

as is usual, to the outlet of a standard manifold or air-fuel mixing device 42, and the lower end of fuel inlet-forming member I2 of said igniter device, which may be cut on the bias to enhance fuel flow thereinto and threaded, being received within and secured to the wall of said device 42 and producing an operative relationship between the flame outlets of said igniterdevice and said burner. The air-fuel mixing chamber provided within manifold 42 carries a standardy fuel iet 44 which is fed with fuel through the proper tubing, shown lat 46, leading from the source (not shown) ofA fluid fuel at hand. If desired,

tubing 46 may be provided with a standard, manually operable valve 48 by means ot which fluid flow into manifold l42 may be selectively controlled. And, between valve 48 and manifold 42 tubing 46 isadapted to carry an electrically operable valve, shown generally at 58, this valve 68 being more or less standard in design in that it is equipped with a chamberv 52 in direct communication with the outlet side of said valve 48, a

chamber 54 in direct communication with said manifold, a valve member 66 operable for controlling fuel iiow from said chamber 62 into said chamber 64, a core 68 secured to said valve member 66 for movement therewith, a magnet body 68 receiving said core and energizable to move same, and a coil -62 operable for energizing said magnet. Incidentally, the normal position of valve member 66 lis that whereat chambers -52 and 64 are cut off from each other, this condition existing during electrical inactivity of coil 62.

Still referring to Figure 4, it will be seen that I provide a transformer, generally indicated at 64, which is of the step-down type because I-intend using a current of relatively low voltage for energizing the coil 32 of my igniter device, this transformer having a primary 66 connected across a service line 68 and a secondary 18 connected by means of leads 12 and 14 to the posts 22 and 28 of said device. Line 68 preferably has a switch `16 arranged therein whereby the energization of primary 66 may be controlled, and it is to be noted that said switch is the sole controlling means for coil 32; in other words, regardless of what happens in the system described herebelow, when switch 16 is closed, coil 32 is energized, and, when switch 16 is open, coil 32 is de-energized. And, when coil 32 is energized by the closing of switch 16, the fuel-air mixture passing through member I2, into duct |8, through ports 38, and into contact with said coil, will become ignited and the resulting ame will be emitted through the outlet end and other outlets I6 of said duct, there to ignite the fuel-air mixture being emitted from burner 48 and thus serve for the most part as a pilot burner.

A relay, generally indicated at 18, has its coil 88 connected in the secondary circuit in series with secondary 18 and coil 32, namely, in the lead 12 which interconnects one side of said secondary and one side of said coil 32, said relay having, in addition to said coil 88, a magnet 82 which is energizable responsive to energization of said coil 88, a core 84 which is movable responsive to energization oi said magnet, anda. switch element 86 which is carried by said core for movement therewith. Switch element 86, upon energization of coil 88 responsive to the closing of switch 16 and the resulting lenergization of secondary 18, is adapted to close a break existing during deenergization of said coil in a lead 88 which is connected at one of its ends to one side of primary 66 and at the other of its ends to another switch element 98 (which is to be described presently). One end of another lead 92 is connected to the opposite side of primary 66, and the opposite end of this lead is connected to one side of the coil 94 of a relay, generally indicated at 96 and to be described presently, the opposite side of said coil being connected by means of a lead 98 to the aforementioned switch element 98. It is seen, therefore, that the closing of switch 16 energizes coils 88 and 32 and that the energization of said coil 88 simultaneously eiiectuates the closing of the gap in lead 88 by means of the resulting movement of switch element 86, the result being that energy flows from one side of primary 66 through the two sections of said lead 88 and the intermediate switch element 86 to switch element 98 and back to said primary from said switch element 98 through lead 98, coil 94 and lead 92.

Series circuit 66-88-86-88-98-98-94- 92-66, which is closed simultaneously with the closing of series circuit 18-12-88-12-32- 14-18, is employed for the purpose of bringing relay 96 into play, the effect of which is to be described presently. This relay is of the delayed action type (the reason, as will soon be seen, being to provide a time interval between the energizing of coil 32 and the opening of valve 58) and is of standard construction, having a magnet |88 whichV isoperable at a predetermined period following the initiation of energy ow through coil 94 for moving a spring-held switch element |82 into play to close a circuit which will soon be described. Switch element |82 has one of its ends permanently connected to an end of a lead |84 connected to lead 88 between switch elements 86 and 98, and the other end of said element |82 is adapted, upon effective energization of magnet |88, to be drawn, against the force of a spring |86, into connection with one end of a lead |88 the other end of which is connected to one side of a solenoid coil ||8. The other side of coil ||8 is connected to lead 92, which interconnects one side of primary 66 and one side of coil 94, by means of leads ||2 and ||4.

When magnet |88 becomes effective to cause interconnection of leads |84 and |88 by means of switch element |82, coil ||8 becomes energized and actuates a core ||6 to which switch element 98 is flxedly connected, and this element 98, to which lead 88 is permanently but resiliently connected, is drawn out of connection with lead 98 and into simultaneous connection with an end of each of two other leads ||8 and |28, the other end of said lead ||8 being connected to said lead |88 between' said switch element |82 and said coil ||8, and the other end of said lead |28 being connected lto one side of coil 62 of electrically operable valve 58. The other side of coil 62 is connected to primary 66 by means of a lead |22 which is connected to leads ||2 and I4.

In short, when switch 16 is closed, igniter element 32 becomes energized and, in addition, switch 86 is caused to close the circuit 66-88- 86-88-98-98--94-92-66 which includes coil 94. Upon the expiration thereafter of a .pre-

determined period (which is, of course, sufficient to permit the temperature of coil 32 to reach a value at least equal to the ignition temperature of the fuel-air mixture which is to pass through duct |8 from manifold 42 upon the opening of valve 58), magnet |88-becomes capable of drawing switch |82 into contact with lead |88 and'thereby place coil ||8 in readiness for energization and the job`of moving switch 98 from its position of contact with lead 98 into position of contact with leads ||8 and 28. The circuit which is closed under the influence of magnet |88 is 66-88--86--88-I84--I82-|88 ||8-||2||4-92-66 and may be termed an initiating circuit for coil ||8, for. it is .reopened immediately upon the breakage of the contact between switch 98 and lead 98 which is influenced by the energization of said coil. However, the energization of coil ||8 continues after the reopening of the initiating circuit therefor, because switch 98 will have closed a "continuing circuit for said coil, namely, 66-88-86-88- 98-I |8|88| |8| |2| |4-92--66. And,

closed simultaneously with the closing of this last mentioned circuit is the parallel valve circuit 66-88-86-88-98-I28-62-I22-I|4 92--66 in which is contained the coil 62 by the energization of which the chambers 52 and 54 in valve 68 are intercommunicated.

The system, therefore, is one wherein the igniter device is of simple, compact and inexpensive construction and the operation of which is economical and gives to said system the highest degree of automaticity and safety under all conditions. The igniter coil 32 is controlled exclusively by switch 16. The igniter coil 32 is caused to acquire the safe and proper temperature before any ignitible fluid is allowed to pass through any part of the system. And, if an electrical break occurs in the circuit which contains the igniter coil32, all of the circuits which contain the transformer primary 66 are opened by the switch 86, which means that there is never any fuel iiowage throughout any part of the system during electrical inactivity of said coil 32.

Whereas Figure 4 shows the igniter device employed as a pilot burner for the main burner 40, Fig. 5 shows it connected, if desired, directly to the manifold 42 so that the mixture passes in its entirety through duct l0 rather than as in said Figure 4.

Although the invention has been described with some detail it is to be understood that such description is for the purpose of illustration only and is not to be taken as definitive of the limits of the inventive idea. The right is reserved to make such changes in the details of construction and arrangement of parts as will fall within the purview of the attached claims.

What I claim is:

- 1. In a fuel ignition system comprising an igniter circuit and a control circuit, a continuously energized igniter in said igniter circuit adapted to be mounted in the path of fuel ow, a magnetically controlled normally open valve in said control circuit for controlling the flow of fuel insaid flow path, a time delay circuit interposed between the control circuit and the igniter circuit, relay switch means in the igniter circuit for closing said time delay circuit upon energization of the igniter circuit, a holding circuit for said control circuit, a time delay relay switch in said time delay circuit for closing said holding circuit a predetermined time interval after the closing of said time delay circuit, a holding circuit for the first-mentioned holding circuit, and a relay switch in said first-mentioned holding circuit for closing said second-mentioned holding circuit to thereby energize the electromagnetically controlled valve and hold said valve in an open position to permit fuel flow along said ow path.

2. In a fuel ignition system comprising an igniter circuit and a control circuit, a continuously energized igniter in said ignition circuit adapted to be mounted in the path of fuel flow, a normally closed electromagnetically controlled valve in said control circuit for controlling the ow of uid in said flow path, a time delay circuit interposed between said igniter circuit and said control circuit, a relay switch operable upon energization of the ignition circuit for energizing said time delay circuit, a time delay solenoid in said time delay circuit, normally closed switch means in said time delay circuit, a holding circuit for said control circuit adapted to be closed upon the energization of said time delay circuit after a predetermined time interval, switch means in said holding circuit operable upon energization of said time delay solenoid for closing said holding circuit, a holding relay in said holding circuit for controlling said normally closed switch means to interrupt said time delay circuit upon energization of said holding circuit, and a holding circuit for the first-mentioned holding circuit controlled by the holding relay therein for holding the rst-mentioned holding circuit closed and the electromagnetically controlled valve open.

3. In a fuel ignition system comprising an igniter circuit and a control circuit, a continuously energized igniter element in said igniter circuit adapted to be mounted in the path of fuel flow, a magnetically controlled valve in said control circuit for controlling the ilow of fuel in said flow path, a time delay circuit interposed between the control circuit and the igniter circuit, 4a relay switch in said igniter circuit for closing said time delay circuit when said igniter circuit is energized, a holding circuit for said control circuit, a time delay relay element in the time delay circuit adapted to energize the holding circuit a predetermined time interval after energization of said time delay relay element, a holding relay in said holding circuit, a second holding circuit for said electromagnetically controlled valve, and switch means controlled by said holding relay for interrupting the time delay circuit and' maintaining said second-mentioned holding circuit closed, whereby said magnetically controlled valve will be opened after the igniter has reached a state of incandescence and will be held in an open position until failure of said igniter element.

vERNmA. Fox 

